\mathbf. It’s consistent with \mathrm for well-defined constants

Mathbf, cause we’re best friends.

Neither, I just write a symbol.

Arrows are more descriptive. \vec is better.

If you like mathbf more then at least redefine vec and use vec. Keeps the code more tidy.

No idea what this is but /vec is easier to write so I choose you Pokémon /vec

I haven’t heard those names in a long time…

All in with the crabs.